Meet the hair loss expert

Dr. Robert Leonard has specialized in hair loss and restoration for more than 23 years. He is a past president and a member of the Board of Governors of the International Society of Hair Restoration Surgery, a Diplomat of the American Board of Hair Restoration Surgery, and a Fellow of the American Academy of Cosmetic Surgery. Dr. Leonard has treated men and women suffering from hair loss with medical therapies, including ROGAINE® products, with great success.

Advice from the expert

Watch Dr. Leonard, a hair growth expert, talk about why he recommends ROGAINE® products and the best way for you to see results.

Q&A with the expert

Get an expert's take on the causes of hair loss, and other ways to support hair health and growth in Dr. Leonard's Q&A.

DR. LEONARD: Most people lose between 50–100 hairs a day, which is considered normal hair loss. This is replaced with new hair through the three stages of natural hair growth: anagen (growth phase), catagen (transitional phase) and telogen (resting phase). A consistent loss of 150 hairs a day is considered significant hair loss. If you start to notice more hair than usual in your shower drain, on your pillow, or in your hairbrush, then you may be experiencing hair loss/thinning.

DR. LEONARD: This hair loss may be due to an autoimmune condition called Alopecia Areata, in which you lose a great deal of hair in a short amount of time. Alopecia Areata is distinct from Hereditary Hair Loss. This type of hair loss is so extreme, it is best to take proactive measures.

DR. LEONARD: Crash dieting can, indeed, cause reactive hair loss. This reactive hair loss (called Telogen Effluvium) is different from Hereditary Hair Loss, however. Hereditary Hair Loss is the most common form of hair loss, and accounts for the majority of all cases in both men and women.

Telogen Effluvium is limited and temporary hair loss that will grow back on its own. In all, it takes about three to four months for the hair to shed, and then an additional three to four months for the hair to regrow from Telogen Effluvium.

Other conditions that can cause Telogen Effluvium include: anemia, pregnancy, general anesthesia and trauma.

If you experience Telogen Effluvium, but also have Hereditary Hair Loss, your hair may not grow back as full as it was prior to the temporary loss.

DR. LEONARD: Like crash dieting, a common occurrence of post-pregnancy is hair loss (another form of Telogen Effluvium). Typically, hair will start shedding a few weeks after childbirth, and will then begin the regrowth cycle in three to four months. However, if you have hair loss after pregnancy AND have female pattern hair loss, your hair may not grow back as thick as it was before the temporary hair loss took place.

Can medications cause hair loss? If so, what kinds are associated with hair loss?

DR. LEONARD: Hypo- and hyperthyroidism can both cause thinning hair. It’s important to work with your doctor to treat these hormonal imbalances in order to get thyroid levels back to normal. Once regulated, hair loss will generally subside.

Is there a way to determine if I’m genetically predisposed to hereditary hair loss?

DR. LEONARD: If you have a family history of Hereditary Hair Loss, there is a test available that can assess the risk of pattern baldness before any hair is even lost. The test, called HairDX, is a good tool for young men and women who have a family history of hair loss and wish to be proactive.

If you find that you are genetically pre-disposed to hereditary hair loss. As the saying goes: the early bird catches the worm.

DR. LEONARD: No, the sun will not make hair thinning worse, but it is a good idea to protect your scalp from the sun with a hat or sunscreen. Especially for those with thinning hair, protecting the hair you have becomes vitally important. Protect your hair and scalp from the sun, since exposure to UV makes hair more brittle. Look for UV protectant styling products and wear a hat when you are in the direct sun, which will protect your scalp from burning as well.

DR. LEONARD: Vitamins are important for general health—and by extension, hair health. And while there are many hair vitamins on the market, a good multi-vitamin taken daily will go a long way toward stronger, healthy hair.

Biotin—a natural supplement—is often cited as a natural way to promote healthy hair growth. While Biotin can make hair fibers stronger, it cannot slow down hair loss, nor regrow hair. In fact, Biotin generally benefits nails more than hair.

DR. LEONARD: It’s always in your best interest to eat a balanced diet. Plus, hair is 95% protein, so a high protein diet can help promote healthy hair, especially if you have a protein deficiency. Look for foods such as fish, eggs, beans, and yogurt.